Menstruation — aka having your period — is when blood and tissue from your uterus comes out of your vagina. It usually happens once every month. Your menstrual cycle begins on the first day of your period. Your cycle prepares your body for a possible pregnancy. The average cycle lasts between 24 and 38 days. Women typically get a few signs that their period is about to start. Those include things like abdominal cramps, headache, tender breasts, and changes in bowel movements. Symptoms are typically. Menstruation (also known as a period, among other colloquial terms) is the regular discharge of blood and mucosal tissue from the inner lining of the uterus through the vagina. [1] The menstrual cycle is characterized by the rise and fall of hormones. [1] Menstruation (or period) happens monthly. As the uterus sheds its lining, vaginal bleeding follows. Menstrual blood is made of blood and tissue. PERIOD. is a global youth fueled non-profit which strives to eradicate period poverty and stigma through advocacy, education, and service. Take our free period quiz to find out when your first period might arrive. Answer science-backed questions about puberty signs and get a personalized estimate. The meaning of PERIOD is the completion of a cycle, a series of events, or a single action : conclusion. How to use period in a sentence. Synonym Discussion of Period. PERIOD definition: 1. a length of time: 2. a fixed time during the life of a person or in history: 3. in school, a…. Learn more. Getting a period, or menstruating, occurs about once a month, may come with PMS or PMDD, and may give clues about your overall health.